<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01外边距</title>
    <style>
        /*div {
            width: 100px;
            height: 100px;
            border: 1px solid red;
        }*/

        #d1 {
            /*单独某一个方向赋值*/
            /*     margin-left: 100px;
                 margin-top: 50px;
                 margin-bottom: 50px;;
                 margin-right: 50px;*/
            /**/
            margin: 50px; /*4个方向赋值*/
            margin: 50px 100px; /*上下50 左右100*/
            margin: 10px 20px 30px 40px; /*上右下左*/

        }

        #d2 {
            width: 100px;
            height: 100px;
            border: 1px solid red;
            margin: 50px;
        }

        #big {
            width: 200px;
            height: 200px;
            background-color: green;
            overflow: hidden;
        }

        #big > div {
            width: 50px;
            height: 50px;
            background-color: red;
            margin-left: 50px;
            margin-top: 100px;
        }

        span {
            border: 1px solid blue
        }

        /*行内元素上下外边距无效*/
        #s1 {
            /*margin-top: 50px;*/
            margin-right: 50px;
        }
        #s2{
            margin-left: 50px;
        }
    </style>
</head>
<body>
<span id="s1">span1</span><span id="s2">span2</span>
<div id="big">
    <div></div>
</div>
<div id="d1">div1</div>
<div id="d2">div2</div>
</body>
</html>